11yo DC's birthday coming up. Entertainer does a science show but are not a company. More a one-man-band type of thing. She was poor at answering messenger messages and emails and I don't have her phone number. This was put down to going to a wedding fair which was true.... but still. I'd rather pay half or two thirds beforehand and pay the rest afterwards. Not that I don't trust her but I feel I'm carrying all the responsibility and have no recourse if she say sleeps in. What's the done thing here? Maybe she is used to people not paying up after they've had her services or summat. 10 kids coming and apparently they get some merch, cost around £200. I know I'm not being unreasonable, therefore my question is: even though my stance is not unreasonable what would you do? I feel like just paying for it, but just asking for her number so that is she gets lost, sleeps in, it can be remedied.